Method of and means for repairing lateral branches of sub-surface pipe lines

ABSTRACT

This invention is directed to providing a method of and apparatus for repairing faults and breaches in lateral branches of sub-surface pipe lines into which it is impracticable or impossible to introduce sub-surface pipe line repair apparatus. In accordance with the invention such apparatus is employed in the main line with auxilary apparatus introduced into the lateral branch to provide a combination whereby a fault or breach, hereinafter generically designated fault, constituting the source of infiltration into the lateral and hence into the main can be located, and thereafter by introduction of a chemical repair substance from the main line into the lateral branch and through the fault terminate the infiltration and seal the lateral against further infiltration.

United States Patent [1 1 Wise Jan. 16, 1973 METHOD OF AND MEANS FORREPAIRING LATERAL BRANCHES OF SUB-SURFACE PIPE LINES Inventor: Donald S.Wise, Levittown, Pa.

Assignee: Telafix Incorporated, Levittown, Pa.

Filed: Aug. 5, 1971 Appl. No.: 169,433

US. Cl. ..137ll5, 137/315, 138/97 Int. Cl ..F16l 55/18 Field of Search..137/15, 315; 138/97 References Cited UNITED STATES PATENTS PrimaryExaminer-Martin P. Schwadron Assistant Examiner-David R. MatthewsAttorney-W. Wycliff Walton [57] ABSTRACT This invention is directed toproviding a method of and apparatus for repairing faults and breaches inlateral branches of sub-surface pipe lines into which it isimpracticable or impossible to introduce sub-surface pipe line repairapparatus. In accordance with the invention such apparatus is employedin the main line with auxilary apparatus introduced into the lateralbranch to provide a combination whereby a fault or breach, hereinaftergenerically designated fault, constituting the source of infiltrationinto the lateral and hence into the main can be located, and thereafterby introduction of a chemical repair substance from the main line intothe lateral branch and through the fault terminate the infiltration andseal the lateral against further infiltration.

6 Claims, 2 Drawing Figures PATENTEDJAN 16 I975 FIG.

FIG. 2.

IN VENTOR.

S. WISE ATTORNEY.

DONALD METHOD OF AND MEANS FOR REPAIRING LATERAL BRANCHES OF SUB-SURFACEPIPE LINES CROSS REFERENCES TO RELATED APPLICATION In a co-pendingapplication titled METHOD OF AND MEANS FOR EXAMINING AND REPAIRINGSUB-SURFACE PIPES filed in the US. Patent Office concurrently herewith Ihave disclosed an improved examination and repair unit utilizing thefocal plane of a lens system associated with a television camera in apreferably closed system and indicia on the viewing screen of amonitoring instrument for locating faults in sub-surface pipe lines orthe like. That unit, and the method employed with its aid for examininga sub-surface pipe line, or lines are eminently suitable in accordancewith the present invention for combination and association with otherapparatus for the performance of novel method steps hereinafter morefully described in locating faults in lateral pipe lines into which theexamination and repair unit cannot readily be introduced, and foreffecting their repair.

BACKGROUND OF THE INVENTION 1. Field of the Invention The invention isconcerned with sub-surface pipe line and conduit repair to eliminateflow of ground water and the like into pipe lines and conduits, andespecially examination and repair of lateral branches of main lines onwhich the customary examination and repair units cannot be used. I

2. Description of the Prior Art It has become standard procedure tointroduce a combined examination and repair unit into a sub-surface pipeline or conduit to which access can be had through manholes spaced atintervals longitudinally of the pipe line. These require that access beavailable to at least two such manholes and where a lateral branch suchas a sewer line leading from a single detached dwelling to a sewer mainin the adjacent highway has a fault affording ingress to extraneoussub-surface ground water and the like such unit cannot be introducedinto the lateral or branch line. Hence, it has heretofore been necessaryin such cases to excavate the soil and repair the line by application ofappropriate external expedients, as by replacing a section of the pipeor introducing sealing material into the excavation to surround the pipeat the fault and seal it from without. Apart from the labor and expenseof excavation and concomitant operations this procedure imposesinconvenience in that it is often necessary to declare the lateralbranch unavailable for normal usage while repairs are being made.

SUMMARY OF THE INVENTION The invention is directed to locating a faultor other breach in a lateral sewer line or the like by first using knownprocedures including observation of effluent with aid of a closedcircuit television system, identifying the lateral branch in which thefault exists and then by novel further procedures including introducinginflatable obstructing means into the thus identified lateral branchspecifically locating the fault and introducing plastic material intothe branch from a repair unit in the main for extrusion through thefault to seal the same against further intrusion of ground water or thelike.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing,

F IG. 1 is a diagrammatic vertical section of a sub-surface lateral lineconnecting for example, a residential structure with a sewer main underthe adjacent highway.

FIG. 2 is a fragmentary horizontal section of an enlarged scale showinginflatable means utilized to temporarily exclude flow of liquids fromthe lateral main to facitilate locating a fault or an infiltration pointand while it is being repaired.

DESCRIPTION OF THE PREFERRED EMBODIMENT While I prefer to employ as anexamining and repair unit the apparatus disclosed in my said co-pendingapplication but any other unit capable of more or less comparableperformance may be employed as preferred, provided it comprises anobservation unit, such as a television camera T, electrically connectedthrough a cable C extending in the subterranean main pipe line M with amonitoring unit I on the screen of which an image of the field of viewof the camera may be reproduced, lighting means B carried by the cameraunit T permitting said field to be adequately illuminated for televisionreception by the camera. Energizing power for the camera as well as forthe lighting means B are supplied by flexible conductors, contained incable C and fed with it into the main from a manhole l as the camera andrepair unit is drawn along the main by a hawser H leaving the main froman adjacent manhole. The camera has attached to it for conjoint progressthrough the main'a repair unit R maintained at a predetermined distancein rear of the camera in relation to its direction of travel and aflexible hose fed with cable C through the manhole 1 is connected to asuitable pump (not shown) for extruding plastic grouting into the repairunit and from it into the surrounding space, the repair unit includingalso a pair of axially spaced bladders or inflatable collars 2,2 betweenwhich the exit port 3 for the plastic grouting material is positioned.These collars 2, 2' are connected through a hose H with an air pump (notshown) on the surface adjacent manhole l as is customary, enabling thecollars to be inflated and deflated as desired. This apparatus is allold in the art and need not be more fully described.

Other apparatus adapted for combined operation and association with theforegoing in accordance with the invention, includes flexible inflatablemeans 10 having connected with it an air hose 11 which communicates atits opposite end with a pump 12 or other source of air under pressure, acontrol hawser 14 connected to a winch 15 being built into or attachedto the hose 11 to provide means for controlling the inflatable meanswhen it has been entered into a lateral or branch pipe line.

In the operation of repairing a fault or breach in a lateral or branchpipe line with the aid of apparatus above described and in accordancewith the invention,

the lateral branch L in which the fault F occurs is first examined withthe aid of the examining unit, in accordance with known procedures or asdescribed in my said co-pending application, the appearance on suchexamination of an abnormal flow of liquid from a lateral affordsevidence by which a leaking one may be identified. Fault F in lateral Lin the drawing represents such a breach in the wall of a section of pipecomprised in the branch line while a void V surrounding the pipe in thevicinity of the fault is one of the character of those usually found atsuch locations due to the infiltrating water carrying with it sedimentwashed from the surrounding soil; obviously the fault may be at anylocation along the line, and the void V may be greater or smaller thanas shown depending on conditions.

The offending lateral having been identified with the aid of theexamining unit the inflatable means is introduced into the lateralthrough a clean-out opening 0 and of the type usually found either inthe lowest floor of the adjacent building D or as in FIG. 1 at an accesswell W adjacent to but exteriorly of the building. The inflatable means,uninflated, when so introduced, with the hose 11 and hawser 14 attachedand fed into the line as the inflatable means progresses, usually iscarried along the pipe by the normal flow of water, or an excessive flowof water may be introduced for the purpose if required. When theinflatable means as a result of this operation reaches the main line,and thus can be observed with the aid of the examining unit as havingatained the junction of the branch with the main its further progress isinterrupted by restraint upon the hawser l4 and the inflatable means isthen partially inflated through the hose 1 1 to a degree sufficient toenable it to restrict, or substantially obstruct flow of liquid past it,but without creating so much friction between it and the pipe wall as toprevent its retraction toward the clean out opening with the aid of thehawser 14 and a retracting winch 15. As the inflatable means is drawnthrough the branch line away from the main little or no liquid isobserved flowing into the latter until the said means reaches and passesa fault F through which ground water enters the branch and thereaftermay flow unobstructed into the main. lts appearance at the junction ofthe branch with the main, as observed with the aid of the examiningunit, is evidence that the inflatable means in its movement away fromthe main has passed the fault and at this point further retraction ofthe inflatable means is halted, the air pressure therein is increased topositively obstruct all flow of liquids from upstream in the lateral.The repair unit is then moved in the main to align it with thedownstream end of the branchat its junction with the main and plasticrepair material, for example gel grout A M-9 marketed by AmericanCyanimide Co., is injected through the repair unit into the mainadjacent the end of the lateral, thence into the lateral and through thefault into the surrounding soil. Injection of the repair material iscontinued preferably until it entirely fills the void V whereuponexcessive backpressure in the grout feed line develops, demonstratingthat the void has been filled and further feeding of grout isdiscontinued.

After the void V has been filled, sufficient time is allowed to elapse,if required, to enable the plastic material to congeal or set, theexamination and repair unit is removed from the main, the inflatablemeans deflated and withdrawn from the lateral. Ordinary flushing of thelateral with water is thereupon usually sufficient to carry residualgrout material from the lateral into the main and at least to thenearest downstream manhole affording access to the main, through whichit may be removed, or it may be permitted to be flushed through the mainto its outlet.

At times, the grout material may set in the lateral sufficiently toresist removal by mere flushing with water and in such instanceswaterjet propelled cleaning apparatus may be introduced into the lateralfor clearing the obstruction, after which normal use of the lateral andmain may be resumed, the grouting material in void V in the course oftime usually becoming so rigidly set as to protect that portion of thelateral encased within it fully as efi'ectively as adjacent portions areprotected by the soil surrounding them.

I claim:

1. The method of repairing a fault in a tubular subsurface lateralbranch of a sub-surface conduit which comprises locating the branchcontaining the fault, introducing inflatable means into the branch at apoint remote from the conduit, projecting said means in the branch toits junction with the conduit, inflating said means to therebysubstantially inhibit flow of fluid from the branch to the conduit,retracting said means toward the point of its introduction to the branchto a point between the fault and said point of introduction, discharginginto a restricted portion of the conduit communicating with said brancha grout material until said material fills the branch between saidinflatable means and said junction and is extruded through the fault,then removing the inflatable means from the branch and the conduitrestricting means from the conduit and discharging grout material fromthe branch into the conduit.

2. The method defined in claim 1 in which the branch containing thefault is identified by visual means through observation of a pluralityof junctions of lateral branches with the conduit and that branchobserved to conduct greater than normal quantities of liquid to theconduit is subjected to treatment by the repair steps defined in saidclaim.

3. The method defined in claim 1 in which the inflatable means whenpositioned in the branch between the fault and said point ofintroduction to the branch is further inflated to completely obstructpassage of liquid through the branch.

4. The method defined in claim 1 in which the restricted portion of theconduit into which grout material is discharged is defined by inflatablemeans disposed in the conduit in opposite directions respectively fromsaid junction of the branch and tubular grout material conducting meanscommunicate with said restricted portion within one of said inflatablemeans and with grout material supplying means disposed at the surfaceupwardly from said conduit adjacent an opening therein.

5. The method defined in claim 1 in which the grout material depositedin the branch between the fault and the conduit is discharged into theconduit by the force of a stream of liquid introduced into the branch ata point remote from the conduit.

6. In combination with an examination and repair unit for a sub-surfaceconduit adapted to enter the connected with said inflatable means forsuccessively inflating and deflating the same and means for retractingsaid inflatable means from said junction toward the point of itsinsertion into the branch.

1. The method of repairing a fault in a tubular sub-surface lateralbranch of a sub-surface conduit which comprises locating the branchcontaining the fault, intrOducing inflatable means into the branch at apoint remote from the conduit, projecting said means in the branch toits junction with the conduit, inflating said means to therebysubstantially inhibit flow of fluid from the branch to the conduit,retracting said means toward the point of its introduction to the branchto a point between the fault and said point of introduction, discharginginto a restricted portion of the conduit communicating with said brancha grout material until said material fills the branch between saidinflatable means and said junction and is extruded through the fault,then removing the inflatable means from the branch and the conduitrestricting means from the conduit and discharging grout material fromthe branch into the conduit.
 2. The method defined in claim 1 in whichthe branch containing the fault is identified by visual means throughobservation of a plurality of junctions of lateral branches with theconduit and that branch observed to conduct greater than normalquantities of liquid to the conduit is subjected to treatment by therepair steps defined in said claim.
 3. The method defined in claim 1 inwhich the inflatable means when positioned in the branch between thefault and said point of introduction to the branch is further inflatedto completely obstruct passage of liquid through the branch.
 4. Themethod defined in claim 1 in which the restricted portion of the conduitinto which grout material is discharged is defined by inflatable meansdisposed in the conduit in opposite directions respectively from saidjunction of the branch and tubular grout material conducting meanscommunicate with said restricted portion within one of said inflatablemeans and with grout material supplying means disposed at the surfaceupwardly from said conduit adjacent an opening therein.
 5. The methoddefined in claim 1 in which the grout material deposited in the branchbetween the fault and the conduit is discharged into the conduit by theforce of a stream of liquid introduced into the branch at a point remotefrom the conduit.
 6. In combination with an examination and repair unitfor a sub-surface conduit adapted to enter the conduit and afford avisual image of the conduit at a remote observation point, means forsupplying grouting material to said unit, inflatable means adapted forinsertion in a branch of said conduit and for projection to the junctionof the branch with the conduit, means connected with said inflatablemeans for successively inflating and deflating the same and means forretracting said inflatable means from said junction toward the point ofits insertion into the branch.